Adjust the oven rack to the middle position. Preheat oven 350F. Grease 9x13 inch pan and line with a parchment sling.
In a medium bowl, whisk together flour and baking powder.
In a medium saucepan over medium heat, melt the butter, brown sugar, and salt. Remove from the heat and sir in the coffee until well combined. Let the mixture cool to room temperature. Add the egg and vanilla and whisk until combined. Transfer the mixture to a large bowl. Add the flour mixture and stir until just combined. Add the pecans and chocolate chips and stir gently.
Spread the batter evenly into the prepared pan and bake 18 to 24 minutes, until the blondies are set on the edge and top is golden and brown and just beginning to form cracks. A wooden skewer or toothpick inserted into the blondies should come out with a just a couple crumbs.
Transfer the pan to a wire rack and let cool completely. Use the parchment sling to gently lift the blondies from the pan. Cut them into squares.